The present invention relates to a power conservation device having a power save mode and an image forming apparatus.
Patent Reference has disclosed technology for conserving power of a photo sensor used for an apparatus such as an image forming apparatus. In a case of, for example, a photo interrupter for detecting a sheet, according to the technology disclosed in Patent Reference, a control unit is provided for switching power supply to a light emitting element of the photo interrupter. When the photo interrupter does not need to detect a sheet such as warming up the image forming apparatus or standby, the control unit turns off the power supply.
Patent Reference: Japanese Patent Publication No. 08-204890
In the conventional technology described above, the control unit simply switches on and off the power supply to the light emitting element of the photo interrupter. There is no unit for controlling power supply to the control unit for switching the power supply to the light emitting element of the photo interrupter. The control unit is generally formed of a CPU for controlling a printer engine. Accordingly, when the CPU starts up, a large amount of power is consumed.
In view of the problems described above, an object of the present invention is to provide a power conservation device and an image forming apparatus, in which it is possible to solve the problems of the conventional technology.
Further objects and advantages of the invention will be apparent from the following description of the invention.